In a conventional arrangement of this kind for adapting the power of a gas discharge lamp, as described in German Patent No. 44 39 812, a control device is provided for supplying power to the gas discharge lamp. The control device contains a DC/DC converter that converts a DC voltage into another DC voltage, as well as a bridge circuit, in particular an H bridge, in whose diagonal branch the gas discharge lamp is located. The gas discharge lamp is supplied with AC voltage or alternating current by way of the bridge circuit. Regulation of the power conveyed to the gas discharge lamp is performed. In the event of a reduction in the mean lamp power as compared to rated operation, provision is made for a lengthening of the period of the lamp AC voltage or the lamp alternating current. As a result, the low frequency at which the lamp is operated is decreased even further. This power decrease also serves, if applicable, to protect the control device from overtemperature in order to prevent it from being damaged.
In addition to this conventional lengthening of the period in order to improve the polarity reversal operation at reduced power, and to prevent damaging overtemperatures in the control device, it is also known to ascertain the temperature of a control device using a sensor, and then to limit the maximum output power.